Muffle roasting-furnace.



. PATENTED JUNE v, 1904.v I. MEYER. MUEPLB RoAsTING PURNAGB.

3 BHBETS-BHEET APPLICATION FILED SEPT. l, 19

N0 IODEL.

walls embracing the entire apparatus.

UNITED STATES Patented June '7, 1904.

y EEANZ MEYER, oEv NEW YoEK, N. Y.

MUFFLE ROASTING-FURNACE.

SPECIFICATION forming part of Letters Patent No. 761,691, dated June 7, 1904,

' Application filed September l 1903. Serial No. 171,493. (No model-) To @ZZ whom, it may concern:

Beit known that I, FRANZ MEYER, a subject of the Emperor of Germany, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Muiiie Roasting-Furnaces; and Ido hereby declare the following to be a full, clear, and exact description of the invention, such as will enable" others skilled in the art to which it appertains to make and use the same.

My present invention, which is subsidiary" to my Patent No. 731,114,' dated June 16, 1903, relates to muffie roasting-furnaces, and has for its object to provide a furnace comprising a series 0froasting-chambers each formed as a separate unitary structure, effectively braced 'and anchored against the .disrupting effects of` expansion by means of an inclosing metallic shell lined with refractory material, a heating-furnace common to the series of chambers,suitable flue connections, preferably having expansion-joints between the successive units or chambers of the series, and means for preheating the air for oxidizing the sulfur in the ore.

The invention is illustrated in the accompanying drawings, in which-m Figure 1 is a vertical section through a muti-le furnace comprising three units or roasting-chambers. Fig. 2 is a transverse vertical section through a single unit. Fig.

y 3 is a horizontal section .on the line 3 3 of Fig. 1.

In my former patent, above referred to, is shown a horizontal series of roasting-chambers connected to form a unitary structure of brick or masonry, with continuous inclosing y The present invention is designed to relieve and distribute such expansionzpand contraction strains as are incident to this construction, so that they may be divided up and absorbed among several independent elastic chambers or units.

. Referring to the drawings` the numeral 1 indicates a series of roasting chambers or furnaces arranged in a horizontal row upon a basal foundation or support, which chambers are designed to be heated by a common furnace or equivalent source' of heat. Each chamber forms a separate distinctunit in the series, and the several units are so connected as to be supplied with heatfrom said common furnace. In the preferred form of the invention each unit 1 comprisesanoutercasing 2, of metal, preferably a sectional cylinder or shell of iron or steel, embracing a lining 3, of fire-brick or other refractory material. Each chamber is divided into a plurality of superposed roasting-hearths 5, beneath the lower two of which are heating chambers or fines 4 and 8, respectively, said heating-chambers being connected at the "end of the series'of roasting-chambers 1 1 bya vertical flue 4. The roasting-'hearths 5 are provided with rotary stirrers 6, mounted upon columns 7,

passing vertically through the several hearths -in each roasting-chamber, and the material low by way ofY peripheral and central open-l ings in alternate hearths, sothat the roasting ore passes from one hearth to the next lower of the series in the respective furnaces to suitable discharge-outlets 2O in the lowermost hearth of each series. rlhe stirrer-columns and rabble-arms are preferably formed of seamless drawn-steel tubes, the rabble-teeth, which are of cast-iron, being secured to the arms in any preferred manner. The columns and arms are cooled by drawing or forcing air or water through the hollow tubes according to any of the approved methods.

Heating-furnaces 11 11, located at the lower forward end of the structure, constitute a common source of heat for all of the roastingchambers, an arrangement that effects a uniformand eflicient roasting operation, while it also subserves a material economy in fuel consumption. The products ,of combustion from furnaces 11 11 passinto iues or ch'am-v bers 4 4 below` the lower roasting-heartl1 5 of each unit 1. The respective chambers 4'of telescoping rims or projections 14 l5, formed as continuations of the metal shells 2 2 of adjacent units lined with fire-brick or other refractory material. The space between the abutting ends of the flue-linings is iilled with lire-clay or other loose refractory material that Will ordinarily preserve an eflicient seal at the joint and yet be sufficiently yielding to work out when the joint expands unduly. The heating-chambers 8 of each of the units are also connected by flues 13', each formed with an expansion-joint in substantially the same manner as the corresponding flues connecting the lower heating-chambers 4 4-viz., with teleseoping rims 14 and 15, lined with fire-brick and sealed or luted with lire-clay 16. After traversing the several heatingchambers 4 and 8 in series the products of combustion are discharged by way of stacks 25.

In order to preheat the air whichis admitted in regulable quantities to the roasting-chambers for the purpose of oxidizing the sulfur in the roasting ore, a suitable duct 2l is formed in the bottom and side wall of each hearth, through which duct the air is drawn and discharged in la highly-heated condition by. way of suitable openings 22 into the lowermost hearth of each roasting-chamber.

As the ore is fed to the respective roastingchambers from hoppers 12 it is subjected to a preliminary roasting in the upper hearth, from which it is forced by the rabbles 6, by way of peripheral openings 9, to the intermediate hearth, which is directly heated by the hot gases in subjacent chamber 8. The ore then drops through the central opening 10 upon the lowermost hearth, where it is subjected to the heat from chambers 4 and 8 and to the highly-heated air from duct 21, after which said ore is' discharged at outlet 20. The heating-gases pass from furnaces 1l through chambers 4 4 in series, highly heating the lower hearths 5 from below, thence by vertical iue 4 to chambers 8 8, which are traversed successively by the hot gases on the way to stacks 25. As the individual roasting-chambers or units 1 are subjected to the high heat of the burning gases they are free to expand in all directions, and as the walls are confined within the metal casings 2 breaking or cracking of the structure is avoided. As the sides of adjacent units approach each other the iues 13, by reason of the telescoping joints therein, preserve a proper and efficient connection between the respective heatingchambers.

Having thus described my invention, what I claim is 1. A roasting-furnace, comprising a series of roasting-chambers separated by intervening spaces, a heating-furnace common to the series, and lues for the heating-gas connecting with the heating-furnace at one end and the stack at the other through the successive chambers; substantially as described.

2. A roasting-furnaee, colnprising a series of separate units, each consisting of a metal shell and a refractory lining, a heatingfurnace common to the series, and lilies for the heating-gas connecting' with the heatiiig-furnace at one end and the stack at the other through the successive units; substantially as described.

3. A roasting-furnace, comprising a series of separate units, each made up of a series ol superposed hearths, a metal shell and a refractory lining, a heating-furnace common to the series, and lines connecting with the heatingfurnace at one end and the stack at the other through the successive units; substantially as described.

4. A roasting-furnace, consisting of a row of separate chambers, each formed as a unit, comprising a metal shell, a refractory lining therefor, a series of superposed hearths, and heating-chambers below said hearths, a heating-furnace common to the series, and [lues connecting with the heating-furnace at one end and the stack at the other through the heating-chambers ofthe successive units; substantially as described.

5. A roasti11g-furnace, comprising a series of separate units, a heating-furnace common to the series, flues connecting with tbe heating-furnacev at one end and the stack at the other through the series of units, and expansible flue connections between successive units; substantially as described.

6. A roasting-furnace, comprising a series of separate units, each consisting of a metal shell and a refractory lining, a heatingfu rnacc common to the series, and ilues for the heating-gas connecting with the heating-furnaee at one end and the stack at the other through the successive units and liuc connections between adjacent units, each of said liuc connections comprising lateral teleseoping sections of the shells of adjacent units; substantially as described.

7. A roasting-furnace, comprising a series of separate units, each consisting of a metal shell and a refractory lining, a heating-fu rnaee common to the series, and fiues for the heating-gas connecting the successive nuits, each of said iiues comprising lateral telescoping sections of the shells oi' adjacent units, a refractory lining for said telcscoping sections,

and a suitable luting between the abutting edges of the refractory lining; substantially as described.

In testimony whereof l aiiix my signature in presence of two witnesses.

FRANZ M 'EY ICR..

lVitnesses:

H. ScnwmNslnnxo, G. HARTMANN.

IOO 

